Apple may have managed to thwart the WireLurker Trojan targeting iOS devices, but an earlier version that used Windows malware suggests the attacks are more widespread than previously believed.
In a prepared statement sent to The Wall Street Journal, Apple said it has blocked iOS apps available in a Chinese app store that carried WireLurker, which waits for an iPhone or iPad to be activated and then steals data. The company suggested consumers only obtain iOS apps through “trusted sources” such as its own App Store.
This type of Trojan is aimed at non-jailbroken iOS devices and uses binary file replacement to automatically generate malicious iOS apps, according to a research paper from Palo Alto Networks, which first revealed the Trojan. USB sticks are used to spread the attacks, which is unusual for OS X and iOS security, the researchers said.
The Palo Alto Networks paper also reported that while the creators’ goal is not yet clear, the Trojan is capable of stealing a variety of information and can monitor any iOS device connected via USB to an infected OS X computer.
AppleInsider said hundreds of thousands of users may already have been affected by WireLurker after nearly 470 infected apps were downloaded more than 350,000 times via the China-based Maiyadi App Store.
Even before the attacks on Mac computers surfaced, a variant of WireLurker was using Windows malware, according to a story on ZDNet that quoted researchers from AlienVault Labs. The attackers advertise the Windows malware as pirated versions of popular iOS apps such as Flappy Bird, Minecraft and Facebook, and was hosted on Baidu, a public-cloud search engine in China.
This means that while Apple may have revoked the certificate as part of its enterprise provisioning feature to wipe out WireLurker, the Trojan could be easily revived and may use alternative channels to find its next victims.
A story on Tom’s Guide warned that the Trojan’s creators could easily set up a new command-and-control server or use an alternative certificate.
Besides encouraging users to avoid third-party iOS app stores and to be careful about connecting devices to untrusted Mac computers, a free online tool is available on GitHub to detect WireLurker and hopefully contain the worst of the damage.